Encoding h.264 advice

[panteragstk]

So, I'm going to re-encode my VC-1 files to h.264/avc to get rid of the issues with vc-1 playback being completely unreliable. I know that it will be time consuming, but so is diagnosing these issues. I've tried handbrake and it just continues to scan the file with nothing else happening. I use a very basic encoder, but 3mbit is not enough in the quality dept.

Thoughts?

[Taddeusz]

I use MeGUI on a quad core. Depending on the movie it takes about 6-8 hours to transcode a BD movie.

[stanger89]

I kind of like Staxrip, seems a lot more automated(able) than MeGUI, but with fundamentally the same amount of power.

[panteragstk]

Thanks for the replies. I transcoded my first test movie from vc-1 to a 35mbit h.264 hi profile 5 file and it went well. Except that it took 2 days to finish (one for each pass). Not that cool.

[Taddeusz]

Originally Posted by panteragstk

Thanks for the replies. I transcoded my first test movie from vc-1 to a 35mbit h.264 hi profile 5 file and it went well. Except that it took 2 days to finish (one for each pass). Not that cool.

Why so high? Blu-ray only goes up to Level 4.1. How many reference frames did you specify? You should only be using a max of 4 for full 1080p video.

[panteragstk]

Originally Posted by Taddeusz

Why so high? Blu-ray only goes up to Level 4.1. How many reference frames did you specify? You should only be using a max of 4 for full 1080p video.

It chooses 5 on its own. I wanted to use 4.1, but it works so I don't care. I used 6 ref frames. I'll change to 4 to see what happens, thanks. I'm trying to get an exact copy of the vc-1 stream and so far it has worked well. Any advised on speeding things up without sacrificing quality?

[stanger89]

Well for one, I'd go single pass, quality based. All the playing I've done has been single pass with crf of 18 or 20 (lower is higher quality, higher file sizes). I do that with a Blu-ray profile so the encode doesn't exceed the extender's capabilities. I think you can use a faster x264 preset which will speed things up at the cost of (AFAIK) final size, but not quality.

And if you're using StaxRip or something else AVISynth based you could try using DGdecNV, which uses an nVidia GPU for decoding.

[Taddeusz]

Originally Posted by panteragstk

It chooses 5 on its own. I wanted to use 4.1, but it works so I don't care. I used 6 ref frames. I'll change to 4 to see what happens, thanks. I'm trying to get an exact copy of the vc-1 stream and so far it has worked well. Any advised on speeding things up without sacrificing quality?

That might have to do with the bitrate or the overall settings you're choosing. The level is more generally determined by bitrate and the profile (e.g. Main, advanced) is determined by features (pyramidal b-frames, etc).

Also, keep in mind that no matter how high you crank up the bitrate there will still be lost information no matter how negligible.